


Straight up, with a Twist

by antigrav_vector



Category: Captain America (Movies), Iron Man (Movies), Marvel, The Avengers (Movies), marvel cinematic universite
Genre: ABO dynamics, Alpha!Pepper, Alternate Universe - Canon Divergence, Beta!Tony, Bisexual Character, Bisexual Male Character, Bisexual Steve Rogers, Comic Book Science, Dirty Talk, Double Penetration, Enthusiastic Consentacles, F/M, M/M, Marking, Not Canon Compliant, Omega!Steve, POV Pepper Potts, Polyamory, Polyfidelity, Possessiveness, Super Soldier Serum, Threesome - F/M/M, after some negotiation, non-traditional ABO dynamics, serum enhancements
Language: English
Status: Completed
Published: 2017-08-18
Updated: 2017-08-18
Packaged: 2018-12-16 20:40:10
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,612
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11836644
Author URL: https://archiveofourown.org/users/antigrav_vector/pseuds/antigrav_vector
Summary: The Avengers came across some weird glowing plants during one of their missions, and that has consequences no one expects. Steve, Tony, and Bruce got exposed, but only two of them are showing any kind of symptoms. Such as they are. Pepper doesn't know how to react at first, when she finally finds out exactly what these symptoms are.Both her lovers have tentacles, all of a sudden.They're also doing their best to seduce her.





	Straight up, with a Twist

**Author's Note:**

> Unbetaed. Read at your own risk.

Pepper eyed the bathroom door a trifle warily, listening to the slightly muffled sounds of pleasure her two partners were uttering. The cries were starting to make her hormones perk up and sending warmth flooding through her, but she wasn't quite sure what to do about it.

She and Tony had been together since Vanko, and that was a relationship that both of them had fought for. The two of them together had been the darling power couple of the media but without their third, they'd felt that something was missing. Both of them had privately wished they would find that person who could balance them out fully, but they'd carefully kept up their façade of competence and independence for the many interviews and public appearances they'd been forced to deal with. They'd managed. At least Obie and his machinations had been long out of the picture, by then, and the two of them had had relatively little opposition to deal with on the corporate front. That had made it possible for them to shift a little of their focus away from their respective responsibilities and to one another.

Then Loki and the Chitauri had tried to take over the world, and Steve had more or less fallen into their laps. Tony had had first crack at him, and Pepper had been vaguely jealous of that once she'd found out... and, well, after she'd gotten over he horror and anger about the order Steve had given -- albeit not by choice -- to close that portal, with Tony on the far side. Since then, they'd been slowly finding their way as a trio. It had been a big adjustment for all three of them at first, she admitted to herself as Tony all but screamed Steve's name in the throes of pleasure and sent a shudder through her, but they'd finally more or less found their stride right before the two of her lovers had been called out for a mission by SHIELD.

Tony had told her about it when they'd gotten back. Their mission had gone off almost without a hitch for once. The only weird thing they'd encountered had been some plants that glowed orange when injured, and smelled like cotton candy. No one had been able to identify said plants, including JARVIS. After the team debriefing, Director Fury had kept Steve and his two part-time SHIELD agents back in an attempt to get more information out of them, and dismissed Tony, Thor, and Dr. Banner.

Not long after that, Tony and Steve had started behaving oddly. A day later they'd started touching. Publicly. In ways that Steve had previously been very reluctant to allow outside the bedroom. Pepper knew Tony had less than no problem with that, and probably actively encouraged it. Like any beta, Tony loved sex and was a bit of a hedonist at heart. Not being bound to the rhythms of heat or rut like alphas and omegas made them much freer with their affections, and Tony in particular tended to give unstintingly in that regard.

She and Steve were more reserved, where sex was concerned. Steve thanks to his upbringing in the 20s and 30s, and she because women had to pay attention to things like birth control regardless of their orientation. She wasn't ready to have children, and knew she might never be, though the idea was an appealing one, in the abstract.

Another pleased shout, that time from Steve, made her hands clench at her sides and very nearly broke her resolve not to blindly jump into the situation.

She, as the alpha in their triad, was their emotional caretaker, keeping them balanced and calm. Steve was their omega, their fierce protector. They were counterweights for one another, and she sometimes thought that having Steve join them had somehow stabilised her orbit around Tony, keeping them from imploding or flying apart. The amazing thing about that was the fact that it had worked out like it would have in any other normal triad despite the way that both Steve and Tony were anything but normal. The two of them were so far off baseline normal thanks to their responsibilities as superheros that they might as well be on the Moon, really. But they'd made it work.

Well. Until now. Now, with the way their dynamic was shifting, Pepper felt suddenly unsure. She didn't know what had caused it, where it would lead, or what to do about it -- if anything.

A surprised yelp from Steve, followed by a chuckle from Tony, implied that they were starting another round of fun. Pepper's resolve broke.

Opening the door and stepping through, she started to speak, and stopped dead, the words dying unspoken on her lips. Her lovers were preoccupied with each other, and didn't react to her presence for a few seconds. She used them to gather her wits as best she could.

Eventually, what felt like half an hour later, Tony broke the enthusiastic kiss, probably scenting her, and looked up at her with a very self -satisfied smile. "Pep! Come to join the fun?"

A shudder of mixed desire and confusion went through her as Steve went bright red all the way from his hairline to his collarbones. "Pepper," he squeaked, "I-- we--"

"Shh, sweetheart," Tony hushed him gently, smoothing his hands down Steve's chest. "Pep won't freak out."

Pepper wasn't so sure. "I-- Tony _why do you both have tentacles_?"

Her beta shrugged. "Our best guess is that those weird plants did something to us that no one detected at the time."

Steve nodded. "We haven't come into contact with anything else that could have caused this, so it's really our only lead."

At a bit of a loss, Pepper just stared at them until Tony reached out for her with a wet hand. "It's weird, I know," he told her when she took it almost automatically, "but it doesn't hurt and it's a lot of fun to mess around with."

"You-- Tony, I-- I have no idea what to think." She managed to stutter.

"Don't think, let us ravish you and take your mind off everything that's been stressing you. Steve's been wanting to, but the tentacle thing was making him all unsure. We've been fine the rest of the time, but anytime we want to fuck, we end up losing our land legs."

Steve made a face as Tony threw him under the metaphorical bus. "Shut up, Tony. You were no better."

Well, that much at least was unchanged. The pair of them still bickered like a pair of old ladies, and were still as horny as a pair of teenagers who were just discovering what sex was. "So your solution was to fuck like rabbits?" Pepper asked them sardonically then turned to Tony. "You're acting like Steve's in heat, even though I can't smell heat on him."

"SHIELD's medics won't be much help," Tony pointed out, "Thor has no idea what this is -- I asked him -- and Bruce is already looking into it as best he can, when he's at as much of a loss as Thor. We're pretty sure the Other Guy is keeping him insulated from any effects. No one else on the team came into contact with the things except the three of us. So, since the change appears to be mostly harmless, why shouldn't we enjoy ourselves?"

To make his point, Tony shifted slightly, still holding her hand, without making any other move towards her, and Steve groaned. Pepper only realised then that Tony had worked at least one tentacle into Steve before she'd come in, and hadn't bothered to remove it for their conversation. The renewed touches made Steve's eyes flutter shut as he bit his lip and squirmed, wanting more.

"Tony, don't tease," Steve gritted out, his hands latching onto the sides of the tub and clenching tightly enough that his knuckles went white. His hips thrust up just enough that the tip of his cock -- apparently that was also unchanged -- broke the surface of the water in the tub. Tony made an approving sound in the back of his throat, and Pepper was suddenly damned thankful for her contraceptive implant.

Making an impulsive decision, born of a mix of want, curiousity, and a kind of wild need that seemed to flood through her, Pepper grabbed for the box of condoms they kept around for the days one of them didn't feel like dealing with cleaning up afterwards, and pulled out a few. She ripped one foil packet open as she dropped the rest to the floor within reach and caught Steve's eyes. "Yes?"

Tony groaned at the thought. "I'm all for it."

Steve nodded, the blush that had been receding coming back in force when she immediately slid the condom down over his cock rather than let him change his mind. "Pepper," he said, sounding a bit breathless, "'m not gonna last."

"I don't even care, right now," she shot back, stripping off her slacks and underwear, then her blouse and bra, in efficient movements, "as long as I get to come too."

When she slid into the tub, going down to her knees, with her legs spread so that she could wrap them around Steve's torso, two pairs of hands landed on her waist, steadying her. The sensation of the tentacles against her legs was strange, though, and sent a visceral shudder through her.

"You okay, Pepper?" Steve asked her, as he and Tony paused in their movements so she could get her balance.

The hands on her waist urged her up, and she went with the movement, letting them position her over Steve's cock, then lower her until her sensitive folds pressed down against the head. She held the pose for a moment before putting her hands on Steve's shoulders for leverage and slowly using the grip she had on his hips with her knees to sheathe him. The stretch felt amazing, soothing the building ache of arousal that she'd barely felt into a glow of satisfaction.

Steve's head fell back against the tiled wall behind him with a thump and Pepper winced a little. That had probably hurt. She threaded her hands through his hair and pulled his head back up gently. The bright blue eyes that slid back open to meet hers were dark with desire and Steve's broad chest heaved with the breaths he was taking. His whole body was shaking as he held himself back, and Pepper couldn't help the fond smile that his well-honed restraint always seemed to bring to her lips.

Leaning in to kiss him, she slid her hands down his jaw and held his eyes a beat longer. "Go on," she told him quietly. "Do it."

Tony chuckled at them, and pressed himself in close, plastering himself to Pepper's back in a long line of warm skin. His cock ended up sliding pleasantly between her butt cheeks, and she clenched the muscles there just to hear both of them groan.

It worked, too, Tony shuddered almost convulsively, making a choked sound of enjoyment, and Steve's hips stuttered into motion. The movement reminded her of the new weirdness that had entered their lives, when their intertwined tentacles brushed against the insides of her legs. The feeling made her bite her lip. The smooth almost rubbery skin was similar enough to her toys that she could take it in stride, but the feeling of the suckers? That was more than a little bit confusing and borderline unnerving. Not bad, though. She could feel herself relaxing and accepting the sensation bit by bit. When the suckers latched onto her skin, it felt like someone was trying to leave a few dozen tiny hickeys all at once, making her take a startled hitching breath.

Once she'd catalogued that and come to grips with it, Pepper let her head fall back onto Tony's shoulder, feeling him kiss his way up her neck to nip at her earlobe, his facial hair scratching at her skin, and his subtle pheromones seeming to rise off his skin like cologne. The way she tightened around Steve in response to having Tony -- very deliberately, she was sure -- filling as many her senses as he could at once... Steve made a keening sound in the back of his throat and his hands slid down to her waist. Wrapping around her legs high on her thighs, and lifting her up a couple of inches.

The new position left him just enough space to thrust himself home firmly and grind himself against that point inside that made her leave scratches on his skin. He loved the sting and the red lines she left on his skin, enjoying the marks while they lasted, and enjoying the possessiveness they implied. She loved that he enjoyed it, and that Tony seemed to get off on it as well.

Steve's slow thrusts were rising in tempo, now, and he leaned in to leave a mark of his own at the base of her neck. "Love you," he muttered into her skin before using his strength to lift her up a bit further, so that he could catch her nipple between his teeth and worry at it. It left him fucking her with the head of his cock rather than thrusting deep, but it felt amazing nevertheless. It was as if she'd turned into a raw exposed nerve, somehow.

Pepper's hands flew to wrap around his wrists and she couldn't help the hitching gasp that the sensation pulled out of her. "Steve! Oh, yes, come on," she encouraged him, tilting her hips just so. "More!"

She felt the quirk of a smile against her skin, before Steve was shifting to toy with her other nipple. With their usual synchronicity, Tony reacted too. His hands slid deftly down her flanks and over her belly to rub firmly against her clit and tease at the point where she and Steve were joined. It was enough to send her over the edge, and she came with an almost silent whine. 

Steve followed, curling around her with the force of it, and clenching his teeth hard enough that Pepper swore she heard his jaw creak. When he finally relaxed again, gasping and almost panting for breath, his scent finally rose around her properly to mingle with Tony's.

It was enough to send a small aftershock through her, and she used her knuckle to tilt Steve's head back up for a kiss. "Love you too, sweetheart."

Tony huffed. "And what about me?"

"You," Pepper shot back twisting at the waist to face him as best she could without disengaging, "are entirely too demanding. But I love you, too."

"Good," Tony grinned at her and reached down to start lifting her off Steve. "Come here, then."

Steve let himself go limp with a quiet sigh and Pepper belatedly realised he'd been holding onto the bottom of the tub with his (hopefully temporary) suckers for leverage. When he was stretched out full length, he smiled, languidly pleased with himself and her, and Tony.

After a beat Tony ran his hands back up her sides and around to cup her tits. "Ready for more, Pep?" He asked her.

He was still hard, and Pepper could feel his hips twitching, rubbing his cock against the skin of her lower back. She turned in his arms until they were chest-to-chest, and twined her fingers in his hair. "Always," she laughed and leaned in to kiss him almost chastely, enjoying the way his scent seemed to go darker and take on an edge, "barring injuries or fatigue."

Taking that for the broad hint it was, he sniffed at her in mock-offense, and started doing what he could to rile her back up again. "Good."

Tony's hands started wandering, tweaking at her nipples to make her squirm at the pleasant sting, lingering just long enough in her ticklish spots to make her giggle, then settling on her ass. Pepper returned the playful touches in kind, knowing Tony was probably _aching_ by now, and let her hands clench in Tony's hair, tugging at it in the way she knew he loved, leaning in to bite at the thick muscle between shoulder and neck, untangling her hand from his hair to leave a set of long scratches down the length of his spine then let them linger teasingly low on his back.

The tentacles had replaced his legs, but, oddly, they started just below the hip, rather than at the waist. On the other hand, though, she reflected absently as she let her fingers brush at the crack of Tony's butt, that left her a bit more familiar territory.

The touch sent a shiver through him, and Pepper realised why when she let her fingers trail a little farther down. Steve was also doing his best to tease; there was a tentacle tip just brushing her fingertips, and it didn't budge when she encountered it, stuck tightly to the skin, but Steve jerked, surprised. If he hadn't reacted, Pepper would have assumed the tentacle was Tony's. Tony loved to touch and tease himself when he could. Would definitely have started sucking hickeys into his own skin if he felt like it.

Fumbling a bit, Pepper bent to reach over the side of the tub for another condom. She was definitely up for another round, and knew better than to expect her lover to last forever, teased like this. It was the work of a second to open it and slide it on him. Tony's hips jerked at the touch, and he bit at his lip with a hiss of an indrawn breath, visibly fighting to maintain his control. "Pep! Shit!"

She chuckled at him and tucked her face into the crook of his neck, letting the scent of his skin and his arousal boost her own higher, then lifted her hips just enough to line them up. Before she could drop her hips again, though, another touch made both of them startle. Steve, the devious man, deftly wrapped a tentacle around Tony's cock, letting it spiral up the entire length to coil almost delicately around the tip and tease at her folds in the process.

"You both feel amazin'," he drawled, sounding sex-drunk, then asked belatedly, "this okay?

Pepper didn't answer verbally, taking them both in, in one long stroke. Tony's back arched and he tried to say something that smeared into a low cry instead. Steve groaned, and she took her time savouring the way the tentacle wrapped around Tony changed the way Tony filled her. It left her feeling stuffed full and satisfied in a way she'd never felt before. They'd never tried proper double penetration before, but the way this was making her feel... Pepper might have to bring up the topic.

Having both of her lovers inside her like this was a hell of a turn on. Much more of one than she'd expected, really.

"You both feel amazing," she said on a moan, and started moving. Slowly. "Might have to try this again sometime."

Tony swore and his head fell forward to rest on her shoulder as she moved. Her hand automatically went back into his hair to support him as she fucked herself on what was effectively both of her lovers. Tony's teeth were clenched and his hands were bruisingly tight around her hips as he fought not to come too soon.

Steve shifted, and another tentacle crept up the inside of Pepper's leg. "Another?" He offered.

"Holy fuck," Tony whined.

Pepper raised herself up, and paused in her steady movements. "Hell yes, fuck, Steve," she managed to get out, half-lost in the sensations and scents of her lovers. Maybe she was going to feel this in the morning, but nothing in the world would have stopped her, in that moment. Nothing about this was a bad idea.

The pair of tentacles around Tony made him stretch her wide in a way neither of them alone ever had, and Pepper reveled in it. "Come on," she told Steve, not wanting him to feel left out, "touch yourself. I want you to come with us, this time. Put those strong hands of yours to good use and squeeze your cock the way you feel me squeeze Tony's."

That got her an almost pained wheeze from Tony that might have qualified as a chuckle, had he had the breath for that. "Jesus, Pep," he gritted out between his teeth.

Steve hissed an affirmative and followed directions, his movements bordering on too harsh to feel good.

It didn't take much more for both of them to come, after that, and the way they shuddered against her, caressing and kissing her skin, was just enough to set her off as well.

They leaned against one another as they calmed, their breath coming hard and fast. Tony laughed weakly. "Well, that was better than I could have imagined."

It took a few minutes for any of them to move, and when they did, they had to untangle their limbs carefully. Pepper was damned glad that whatever was causing the transformation waited for them to disengage, before it made her lovers revert to normal. "Mmmm," she agreed, with a hum.

Steve made a face as he stripped off the condom. "Let's get cleaned up."

Tony caught her eyes as he stood, wavering slightly with how wrung out he was by the athletic sex, and added, "I vote we cuddle on the bed."

"No, Tony," Pepper vetoed that idea firmly. "Dinner first. Then maybe cuddles on the sofa."

Actually, some cuddles sounded wonderful, just now. Pepper smiled.


End file.
